A cradle for a personal digital assistant including a connector having a spring-like terminal is conventionally known (for example, refer to Patent Literature 1). According to the cradle for a personal digital assistant, the portable digital assistance and the connector are electrically connected when a connecting terminal of the personal digital assistant is pressed against the spring-like terminal in the case where the personal digital assistant is mounted to the cradle.
Also, a pogo pin connector including multiple mobile pins (pogo pins), which expand or contract by a spring, and a USB connector, in which a USB terminal is directly inserted to a connector, are known.